A study by the scientists from Kew’s botanical gardens in London has revealed that at least one in five of all plant species are endangered. Agriculture is the main culprit. EurActiv’s partner Journal de l’Environnement reports.
More than one fifth of the world’s plant species faces extinction, according to a report published on Tuesday (10 May) by Kew Royal Botanic Gardens in the United Kingdom. Of the endangered species, almost one third are threatened by agricultural activities.
Compiled by a team of more than 80 scientists, this 84-page report is the most complete evaluation of the world’s plants ever carried out. Due to be updated every year, the publication of the State of the World’s Plants report coincided with a scientific symposium on 11 and 12 May at the botanical gardens in the London suburbs.
In their report, the researchers estimated that around 391,000 plant species were known to science (not including varieties of algae or moss), including 369,000 flowering species. This number rises steadily every year: 2,034 new species were identified in 2015. Last year, Brazil, China and Australia were the countries richest in newly-discovered plants, with 235, 158 and 132 new species respectively. Three new plant species were discovered in France.
Of all the plants known to man, 31,128 are so-called ‘useful plants’, used by humans for one purpose or another. Medicinal uses are the commonest (17,810 species). 5,538 different species are eaten by humans and 3,649 by other animals, and 11,365 species are harvested for materials (cotton, linen, etc.).
According to the researchers, 21% of all known plants are at risk of extinction. The primary threat to 31% of these endangered plants is agriculture, through monoculture plantations (for palm oil or rubber, for example) and animal grazing. A further 21% of the endangered species are threatened by the plundering of natural resources, mainly through deforestation.
Then comes urbanisation (habitat loss, tourism, industry), environmental changes (including fires) and invasive species (of which the report identified 4,979). Climate change is the biggest threat to around 10% of endangered plant species, notably those that grow in mountainous regions.